Measurements on a solar greenhouse combining cooling and electrical energy production

Performance results are given of a new type of greenhouse, which combines reflection of near infrared radiation (NIR) with electrical power generation using hybrid photovoltaic cell/thermal collector modules. Besides the generation of electrical and thermal energy, the reflection of the NIR will result in improved climate conditions in the greenhouse. In a previous paper (Sonneveld, P. J., Swinkels, G. L. A. M., Bot, G. P. A., & Flamand, G. (2010). Feasibility study for combining cooling and high grade energy production in a solar greenhouse. Biosystems Engineering, 105, 51–58) a design and feasibility study of this electricity-producing greenhouse was presented. After the description of the construction of this greenhouse, the peak power for Dutch climate circumstances is determined based on the amount of electrical and thermal energy (hot water) produced. The typical yearly yield of this greenhouse system is determined as a total electrical energy of 20 kW h m−2 and a thermal energy of 160 kW h m−2. Improvements are possible in the spectral range of the NIR film and in the focusing unit of the system. In future the improved electricity-producing greenhouse system could generate 31 kW h m−2 of electrical energy and 270 kW h m−2 of thermal energy, so it could operate independent of fossil fuels.